Load Development Overpressure Stop Point

[Supersum1]

New to reloading, starting my first load development. Starting with .308 win, 175gr TMKs, FGMM brass, CCI #200 primers, and Varget.

I was wondering what overpressure sign(s) spell the stop point of load development. What overpressure sign makes you say "alright, this load is as hot as I'm willing or would want to go"? And, for 3/5/+ shot per load tests, do you stop when any case of a certain load reaches that point or only if multiple cases of a load show signs? Any pictures to illustrate what you're looking for would be greatly appreciated.

 

[clcustom1911]

For me, I stick with loads that:

1. Do not cause stiff bolt lift or sticky extraction

2. Don't Cause ejector swipe/embossing

Primer cratering/flattening is a somewhat unreliable sign of a beginning sign of top end of pressure.

If I can get a load that avoids all of the above, groups well, and has good SD/ES numbers, then that's what I would ideally go after.

When you get up toward the top end of pressure, you might have 1 or 2 out of 5 that have sticky bolt signs, etc. You can shoot those, but the brass life and barrel life will be considerably shorter.

 

[XLR308]

To add to the above list is measuring case head expansion.
This has to be done with new brass measured with a blade Mic and a resolution of .0001" before and after firing and must be done in a precise manner to get accurate results.

 

[RackOpsTactical]

Check out the book by Glen Zediker Top-Grade Ammo. Well worth the price of admission. He talks about this and shows pictures. This book should be required reading for reloaders.

Also a nice to have is the quickload software. You can estimate where pressure should be. I've found it to be very reliable.

 

[Supersubes]

Keep in mind we’re still in the cold season, so if you’re loading near max, hot summer weather will likely push you over max. Also, federal brass is about the softest domestic brass made. Like silly puddy soft! It will show pressure before virtually anything else.

 

[clcustom1911]

It will show pressure before virtually anything else.

That's not necessarily a bad thing in my opinion.

 

[Supersubes]

That's not necessarily a bad thing in my opinion.

Perhaps, but putting work into brass that’s gonna shit it’s primer pocket in two or three loads, sucks.

 

[Supersum1]

Perhaps, but putting work into brass that’s gonna shit it’s primer pocket in two or three loads, sucks.

Honestly, that's why I'm using this brass right now. It's my first load development. I'd rather work through it with brass I have leftover from factory ammo; make all my mistakes and do the learning now, then upgrade to better brass later when I have more experience.